/* * Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the OpenSSL license (the "License"). You may not use * this file except in compliance with the License. You can obtain a copy * in the file LICENSE in the source distribution or at * https://www.openssl.org/source/license.html */ #include #include #include #include #include #include #include #include "internal/numbers.h" #include "asn1_local.h" /* * Constructed types with a recursive definition (such as can be found in PKCS7) * could eventually exceed the stack given malicious input with excessive * recursion. Therefore we limit the stack depth. This is the maximum number of * recursive invocations of asn1_item_embed_d2i(). */ #define ASN1_MAX_CONSTRUCTED_NEST 30 static int asn1_item_embed_d2i(ASN1_VALUE **pval, const unsigned char **in, long len, const ASN1_ITEM *it, int tag, int aclass, char opt, ASN1_TLC *ctx, int depth); static int asn1_check_eoc(const unsigned char **in, long len); static int asn1_find_end(const unsigned char **in, long len, char inf); static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len, char inf, int tag, int aclass, int depth); static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen); static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, char *inf, char *cst, const unsigned char **in, long len, int exptag, int expclass, char opt, ASN1_TLC *ctx); static int asn1_template_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len, const ASN1_TEMPLATE *tt, char opt, ASN1_TLC *ctx, int depth); static int asn1_template_noexp_d2i(ASN1_VALUE **val, const unsigned char **in, long len, const ASN1_TEMPLATE *tt, char opt, ASN1_TLC *ctx, int depth); static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, const unsigned char **in, long len, const ASN1_ITEM *it, int tag, int aclass, char opt, ASN1_TLC *ctx); static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, int utype, char *free_cont, const ASN1_ITEM *it); /* Table to convert tags to bit values, used for MSTRING type */ static const unsigned long tag2bit[32] = { /* tags 0 - 3 */ 0, 0, 0, B_ASN1_BIT_STRING, /* tags 4- 7 */ B_ASN1_OCTET_STRING, 0, 0, B_ASN1_UNKNOWN, /* tags 8-11 */ B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, /* tags 12-15 */ B_ASN1_UTF8STRING, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, /* tags 16-19 */ B_ASN1_SEQUENCE, 0, B_ASN1_NUMERICSTRING, B_ASN1_PRINTABLESTRING, /* tags 20-22 */ B_ASN1_T61STRING, B_ASN1_VIDEOTEXSTRING, B_ASN1_IA5STRING, /* tags 23-24 */ B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME, /* tags 25-27 */ B_ASN1_GRAPHICSTRING, B_ASN1_ISO64STRING, B_ASN1_GENERALSTRING, /* tags 28-31 */ B_ASN1_UNIVERSALSTRING, B_ASN1_UNKNOWN, B_ASN1_BMPSTRING, B_ASN1_UNKNOWN, }; unsigned long ASN1_tag2bit(int tag) { if ((tag < 0) || (tag > 30)) return 0; return tag2bit[tag]; } /* Macro to initialize and invalidate the cache */ #define asn1_tlc_clear(c) if (c) (c)->valid = 0 /* Version to avoid compiler warning about 'c' always non-NULL */ #define asn1_tlc_clear_nc(c) (c)->valid = 0 /* * Decode an ASN1 item, this currently behaves just like a standard 'd2i' * function. 'in' points to a buffer to read the data from, in future we * will have more advanced versions that can input data a piece at a time and * this will simply be a special case. */ ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval, const unsigned char **in, long len, const ASN1_ITEM *it) { ASN1_TLC c; ASN1_VALUE *ptmpval = NULL; if (!pval) pval = &ptmpval; asn1_tlc_clear_nc(&c); if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0) return *pval; return NULL; } int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len, const ASN1_ITEM *it, int tag, int aclass, char opt, ASN1_TLC *ctx) { int rv; rv = asn1_item_embed_d2i(pval, in, len, it, tag, aclass, opt, ctx, 0); if (rv <= 0) ASN1_item_ex_free(pval, it); return rv; } /* * Decode an item, taking care of IMPLICIT tagging, if any. If 'opt' set and * tag mismatch return -1 to handle OPTIONAL */ static int asn1_item_embed_d2i(ASN1_VALUE **pval, const unsigned char **in, long len, const ASN1_ITEM *it, int tag, int aclass, char opt, ASN1_TLC *ctx, int depth) { const ASN1_TEMPLATE *tt, *errtt = NULL; const ASN1_EXTERN_FUNCS *ef; const ASN1_AUX *aux = it->funcs; ASN1_aux_cb *asn1_cb; const unsigned char *p = NULL, *q; unsigned char oclass; char seq_eoc, seq_nolen, cst, isopt; long tmplen; int i; int otag; int ret = 0; ASN1_VALUE **pchptr; if (!pval) return 0; if (aux && aux->asn1_cb) asn1_cb = aux->asn1_cb; else asn1_cb = 0; if (++depth > ASN1_MAX_CONSTRUCTED_NEST) { ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_NESTED_TOO_DEEP); goto err; } switch (it->itype) { case ASN1_ITYPE_PRIMITIVE: if (it->templates) { /* * tagging or OPTIONAL is currently illegal on an item template * because the flags can't get passed down. In practice this * isn't a problem: we include the relevant flags from the item * template in the template itself. */ if ((tag != -1) || opt) { ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE); goto err; } return asn1_template_ex_d2i(pval, in, len, it->templates, opt, ctx, depth); } return asn1_d2i_ex_primitive(pval, in, len, it, tag, aclass, opt, ctx); case ASN1_ITYPE_MSTRING: /* * It never makes sense for multi-strings to have implicit tagging, so * if tag != -1, then this looks like an error in the template. */ if (tag != -1) { ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_BAD_TEMPLATE); goto err; } p = *in; /* Just read in tag and class */ ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL, &p, len, -1, 0, 1, ctx); if (!ret) { ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR); goto err; } /* Must be UNIVERSAL class */ if (oclass != V_ASN1_UNIVERSAL) { /* If OPTIONAL, assume this is OK */ if (opt) return -1; ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MSTRING_NOT_UNIVERSAL); goto err; } /* Check tag matches bit map */ if (!(ASN1_tag2bit(otag) & it->utype)) { /* If OPTIONAL, assume this is OK */ if (opt) return -1; ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MSTRING_WRONG_TAG); goto err; } return asn1_d2i_ex_primitive(pval, in, len, it, otag, 0, 0, ctx); case ASN1_ITYPE_EXTERN: /* Use new style d2i */ ef = it->funcs; return ef->asn1_ex_d2i(pval, in, len, it, tag, aclass, opt, ctx); case ASN1_ITYPE_CHOICE: /* * It never makes sense for CHOICE types to have implicit tagging, so * if tag != -1, then this looks like an error in the template. */ if (tag != -1) { ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_BAD_TEMPLATE); goto err; } if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL)) goto auxerr; if (*pval) { /* Free up and zero CHOICE value if initialised */ i = asn1_get_choice_selector(pval, it); if ((i >= 0) && (i < it->tcount)) { tt = it->templates + i; pchptr = asn1_get_field_ptr(pval, tt); asn1_template_free(pchptr, tt); asn1_set_choice_selector(pval, -1, it); } } else if (!ASN1_item_ex_new(pval, it)) { ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR); goto err; } /* CHOICE type, try each possibility in turn */ p = *in; for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { pchptr = asn1_get_field_ptr(pval, tt); /* * We mark field as OPTIONAL so its absence can be recognised. */ ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx, depth); /* If field not present, try the next one */ if (ret == -1) continue; /* If positive return, read OK, break loop */ if (ret > 0) break; /* * Must be an ASN1 parsing error. * Free up any partial choice value */ asn1_template_free(pchptr, tt); errtt = tt; ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR); goto err; } /* Did we fall off the end without reading anything? */ if (i == it->tcount) { /* If OPTIONAL, this is OK */ if (opt) { /* Free and zero it */ ASN1_item_ex_free(pval, it); return -1; } ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_NO_MATCHING_CHOICE_TYPE); goto err; } asn1_set_choice_selector(pval, i, it); if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL)) goto auxerr; *in = p; return 1; case ASN1_ITYPE_NDEF_SEQUENCE: case ASN1_ITYPE_SEQUENCE: p = *in; tmplen = len; /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */ if (tag == -1) { tag = V_ASN1_SEQUENCE; aclass = V_ASN1_UNIVERSAL; } /* Get SEQUENCE length and update len, p */ ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst, &p, len, tag, aclass, opt, ctx); if (!ret) { ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR); goto err; } else if (ret == -1) return -1; if (aux && (aux->flags & ASN1_AFLG_BROKEN)) { len = tmplen - (p - *in); seq_nolen = 1; } /* If indefinite we don't do a length check */ else seq_nolen = seq_eoc; if (!cst) { ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_SEQUENCE_NOT_CONSTRUCTED); goto err; } if (!*pval && !ASN1_item_ex_new(pval, it)) { ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ERR_R_NESTED_ASN1_ERROR); goto err; } if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL)) goto auxerr; /* Free up and zero any ADB found */ for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { if (tt->flags & ASN1_TFLG_ADB_MASK) { const ASN1_TEMPLATE *seqtt; ASN1_VALUE **pseqval; seqtt = asn1_do_adb(pval, tt, 0); if (seqtt == NULL) continue; pseqval = asn1_get_field_ptr(pval, seqtt); asn1_template_free(pseqval, seqtt); } } /* Get each field entry */ for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { const ASN1_TEMPLATE *seqtt; ASN1_VALUE **pseqval; seqtt = asn1_do_adb(pval, tt, 1); if (seqtt == NULL) goto err; pseqval = asn1_get_field_ptr(pval, seqtt); /* Have we ran out of data? */ if (!len) break; q = p; if (asn1_check_eoc(&p, len)) { if (!seq_eoc) { ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_UNEXPECTED_EOC); goto err; } len -= p - q; seq_eoc = 0; q = p; break; } /* * This determines the OPTIONAL flag value. The field cannot be * omitted if it is the last of a SEQUENCE and there is still * data to be read. This isn't strictly necessary but it * increases efficiency in some cases. */ if (i == (it->tcount - 1)) isopt = 0; else isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL); /* * attempt to read in field, allowing each to be OPTIONAL */ ret = asn1_template_ex_d2i(pseqval, &p, len, seqtt, isopt, ctx, depth); if (!ret) { errtt = seqtt; goto err; } else if (ret == -1) { /* * OPTIONAL component absent. Free and zero the field. */ asn1_template_free(pseqval, seqtt); continue; } /* Update length */ len -= p - q; } /* Check for EOC if expecting one */ if (seq_eoc && !asn1_check_eoc(&p, len)) { ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_MISSING_EOC); goto err; } /* Check all data read */ if (!seq_nolen && len) { ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_SEQUENCE_LENGTH_MISMATCH); goto err; } /* * If we get here we've got no more data in the SEQUENCE, however we * may not have read all fields so check all remaining are OPTIONAL * and clear any that are. */ for (; i < it->tcount; tt++, i++) { const ASN1_TEMPLATE *seqtt; seqtt = asn1_do_adb(pval, tt, 1); if (seqtt == NULL) goto err; if (seqtt->flags & ASN1_TFLG_OPTIONAL) { ASN1_VALUE **pseqval; pseqval = asn1_get_field_ptr(pval, seqtt); asn1_template_free(pseqval, seqtt); } else { errtt = seqtt; ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_FIELD_MISSING); goto err; } } /* Save encoding */ if (!asn1_enc_save(pval, *in, p - *in, it)) goto auxerr; if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL)) goto auxerr; *in = p; return 1; default: return 0; } auxerr: ASN1err(ASN1_F_ASN1_ITEM_EMBED_D2I, ASN1_R_AUX_ERROR); err: if (errtt) ERR_add_error_data(4, "Field=", errtt->field_name, ", Type=", it->sname); else ERR_add_error_data(2, "Type=", it->sname); return 0; } /* * Templates are handled with two separate functions. One handles any * EXPLICIT tag and the other handles the rest. */ static int asn1_template_ex_d2i(ASN1_VALUE **val, const unsigned char **in, long inlen, const ASN1_TEMPLATE *tt, char opt, ASN1_TLC *ctx, int depth) { int flags, aclass; int ret; long len; const unsigned char *p, *q; char exp_eoc; if (!val) return 0; flags = tt->flags; aclass = flags & ASN1_TFLG_TAG_CLASS; p = *in; /* Check if EXPLICIT tag expected */ if (flags & ASN1_TFLG_EXPTAG) { char cst; /* * Need to work out amount of data available to the inner content and * where it starts: so read in EXPLICIT header to get the info. */ ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst, &p, inlen, tt->tag, aclass, opt, ctx); q = p; if (!ret) { ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR); return 0; } else if (ret == -1) return -1; if (!cst) { ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED); return 0; } /* We've found the field so it can't be OPTIONAL now */ ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx, depth); if (!ret) { ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR); return 0; } /* We read the field in OK so update length */ len -= p - q; if (exp_eoc) { /* If NDEF we must have an EOC here */ if (!asn1_check_eoc(&p, len)) { ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ASN1_R_MISSING_EOC); goto err; } } else { /* * Otherwise we must hit the EXPLICIT tag end or its an error */ if (len) { ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ASN1_R_EXPLICIT_LENGTH_MISMATCH); goto err; } } } else return asn1_template_noexp_d2i(val, in, inlen, tt, opt, ctx, depth); *in = p; return 1; err: return 0; } static int asn1_template_noexp_d2i(ASN1_VALUE **val, const unsigned char **in, long len, const ASN1_TEMPLATE *tt, char opt, ASN1_TLC *ctx, int depth) { int flags, aclass; int ret; ASN1_VALUE *tval; const unsigned char *p, *q; if (!val) return 0; flags = tt->flags; aclass = flags & ASN1_TFLG_TAG_CLASS; p = *in; q = p; /* * If field is embedded then val needs fixing so it is a pointer to * a pointer to a field. */ if (tt->flags & ASN1_TFLG_EMBED) { tval = (ASN1_VALUE *)val; val = &tval; } if (flags & ASN1_TFLG_SK_MASK) { /* SET OF, SEQUENCE OF */ int sktag, skaclass; char sk_eoc; /* First work out expected inner tag value */ if (flags & ASN1_TFLG_IMPTAG) { sktag = tt->tag; skaclass = aclass; } else { skaclass = V_ASN1_UNIVERSAL; if (flags & ASN1_TFLG_SET_OF) sktag = V_ASN1_SET; else sktag = V_ASN1_SEQUENCE; } /* Get the tag */ ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL, &p, len, sktag, skaclass, opt, ctx); if (!ret) { ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); return 0; } else if (ret == -1) return -1; if (!*val) *val = (ASN1_VALUE *)sk_ASN1_VALUE_new_null(); else { /* * We've got a valid STACK: free up any items present */ STACK_OF(ASN1_VALUE) *sktmp = (STACK_OF(ASN1_VALUE) *)*val; ASN1_VALUE *vtmp; while (sk_ASN1_VALUE_num(sktmp) > 0) { vtmp = sk_ASN1_VALUE_pop(sktmp); ASN1_item_ex_free(&vtmp, ASN1_ITEM_ptr(tt->item)); } } if (!*val) { ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE); goto err; } /* Read as many items as we can */ while (len > 0) { ASN1_VALUE *skfield; q = p; /* See if EOC found */ if (asn1_check_eoc(&p, len)) { if (!sk_eoc) { ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_UNEXPECTED_EOC); goto err; } len -= p - q; sk_eoc = 0; break; } skfield = NULL; if (!asn1_item_embed_d2i(&skfield, &p, len, ASN1_ITEM_ptr(tt->item), -1, 0, 0, ctx, depth)) { ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); /* |skfield| may be partially allocated despite failure. */ ASN1_item_free(skfield, ASN1_ITEM_ptr(tt->item)); goto err; } len -= p - q; if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val, skfield)) { ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE); ASN1_item_free(skfield, ASN1_ITEM_ptr(tt->item)); goto err; } } if (sk_eoc) { ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC); goto err; } } else if (flags & ASN1_TFLG_IMPTAG) { /* IMPLICIT tagging */ ret = asn1_item_embed_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, ctx, depth); if (!ret) { ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); goto err; } else if (ret == -1) return -1; } else { /* Nothing special */ ret = asn1_item_embed_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item), -1, 0, opt, ctx, depth); if (!ret) { ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR); goto err; } else if (ret == -1) return -1; } *in = p; return 1; err: return 0; } static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, const unsigned char **in, long inlen, const ASN1_ITEM *it, int tag, int aclass, char opt, ASN1_TLC *ctx) { int ret = 0, utype; long plen; char cst, inf, free_cont = 0; const unsigned char *p; BUF_MEM buf = { 0, NULL, 0, 0 }; const unsigned char *cont = NULL; long len; if (!pval) { ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL); return 0; /* Should never happen */ } if (it->itype == ASN1_ITYPE_MSTRING) { utype = tag; tag = -1; } else utype = it->utype; if (utype == V_ASN1_ANY) { /* If type is ANY need to figure out type from tag */ unsigned char oclass; if (tag >= 0) { ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_TAGGED_ANY); return 0; } if (opt) { ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_OPTIONAL_ANY); return 0; } p = *in; ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL, &p, inlen, -1, 0, 0, ctx); if (!ret) { ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR); return 0; } if (oclass != V_ASN1_UNIVERSAL) utype = V_ASN1_OTHER; } if (tag == -1) { tag = utype; aclass = V_ASN1_UNIVERSAL; } p = *in; /* Check header */ ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst, &p, inlen, tag, aclass, opt, ctx); if (!ret) { ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR); return 0; } else if (ret == -1) return -1; ret = 0; /* SEQUENCE, SET and "OTHER" are left in encoded form */ if ((utype == V_ASN1_SEQUENCE) || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) { /* * Clear context cache for type OTHER because the auto clear when we * have a exact match won't work */ if (utype == V_ASN1_OTHER) { asn1_tlc_clear(ctx); } /* SEQUENCE and SET must be constructed */ else if (!cst) { ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_TYPE_NOT_CONSTRUCTED); return 0; } cont = *in; /* If indefinite length constructed find the real end */ if (inf) { if (!asn1_find_end(&p, plen, inf)) goto err; len = p - cont; } else { len = p - cont + plen; p += plen; } } else if (cst) { if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER || utype == V_ASN1_ENUMERATED) { ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_TYPE_NOT_PRIMITIVE); return 0; } /* Free any returned 'buf' content */ free_cont = 1; /* * Should really check the internal tags are correct but some things * may get this wrong. The relevant specs say that constructed string * types should be OCTET STRINGs internally irrespective of the type. * So instead just check for UNIVERSAL class and ignore the tag. */ if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0)) { goto err; } len = buf.length; /* Append a final null to string */ if (!BUF_MEM_grow_clean(&buf, len + 1)) { ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_MALLOC_FAILURE); goto err; } buf.data[len] = 0; cont = (const unsigned char *)buf.data; } else { cont = p; len = plen; p += plen; } /* We now have content length and type: translate into a structure */ /* asn1_ex_c2i may reuse allocated buffer, and so sets free_cont to 0 */ if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it)) goto err; *in = p; ret = 1; err: if (free_cont) OPENSSL_free(buf.data); return ret; } /* Translate ASN1 content octets into a structure */ static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, int utype, char *free_cont, const ASN1_ITEM *it) { ASN1_VALUE **opval = NULL; ASN1_STRING *stmp; ASN1_TYPE *typ = NULL; int ret = 0; const ASN1_PRIMITIVE_FUNCS *pf; ASN1_INTEGER **tint; pf = it->funcs; if (pf && pf->prim_c2i) return pf->prim_c2i(pval, cont, len, utype, free_cont, it); /* If ANY type clear type and set pointer to internal value */ if (it->utype == V_ASN1_ANY) { if (!*pval) { typ = ASN1_TYPE_new(); if (typ == NULL) goto err; *pval = (ASN1_VALUE *)typ; } else typ = (ASN1_TYPE *)*pval; if (utype != typ->type) ASN1_TYPE_set(typ, utype, NULL); opval = pval; pval = &typ->value.asn1_value; } switch (utype) { case V_ASN1_OBJECT: if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len)) goto err; break; case V_ASN1_NULL: if (len) { ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_NULL_IS_WRONG_LENGTH); goto err; } *pval = (ASN1_VALUE *)1; break; case V_ASN1_BOOLEAN: if (len != 1) { ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BOOLEAN_IS_WRONG_LENGTH); goto err; } else { ASN1_BOOLEAN *tbool; tbool = (ASN1_BOOLEAN *)pval; *tbool = *cont; } break; case V_ASN1_BIT_STRING: if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len)) goto err; break; case V_ASN1_INTEGER: case V_ASN1_ENUMERATED: tint = (ASN1_INTEGER **)pval; if (!c2i_ASN1_INTEGER(tint, &cont, len)) goto err; /* Fixup type to match the expected form */ (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG); break; case V_ASN1_OCTET_STRING: case V_ASN1_NUMERICSTRING: case V_ASN1_PRINTABLESTRING: case V_ASN1_T61STRING: case V_ASN1_VIDEOTEXSTRING: case V_ASN1_IA5STRING: case V_ASN1_UTCTIME: case V_ASN1_GENERALIZEDTIME: case V_ASN1_GRAPHICSTRING: case V_ASN1_VISIBLESTRING: case V_ASN1_GENERALSTRING: case V_ASN1_UNIVERSALSTRING: case V_ASN1_BMPSTRING: case V_ASN1_UTF8STRING: case V_ASN1_OTHER: case V_ASN1_SET: case V_ASN1_SEQUENCE: default: if (utype == V_ASN1_BMPSTRING && (len & 1)) { ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BMPSTRING_IS_WRONG_LENGTH); goto err; } if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) { ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH); goto err; } /* All based on ASN1_STRING and handled the same */ if (!*pval) { stmp = ASN1_STRING_type_new(utype); if (stmp == NULL) { ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE); goto err; } *pval = (ASN1_VALUE *)stmp; } else { stmp = (ASN1_STRING *)*pval; stmp->type = utype; } /* If we've already allocated a buffer use it */ if (*free_cont) { OPENSSL_free(stmp->data); stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */ stmp->length = len; *free_cont = 0; } else { if (!ASN1_STRING_set(stmp, cont, len)) { ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE); ASN1_STRING_free(stmp); *pval = NULL; goto err; } } break; } /* If ASN1_ANY and NULL type fix up value */ if (typ && (utype == V_ASN1_NULL)) typ->value.ptr = NULL; ret = 1; err: if (!ret) { ASN1_TYPE_free(typ); if (opval) *opval = NULL; } return ret; } /* * This function finds the end of an ASN1 structure when passed its maximum * length, whether it is indefinite length and a pointer to the content. This * is more efficient than calling asn1_collect because it does not recurse on * each indefinite length header. */ static int asn1_find_end(const unsigned char **in, long len, char inf) { uint32_t expected_eoc; long plen; const unsigned char *p = *in, *q; /* If not indefinite length constructed just add length */ if (inf == 0) { *in += len; return 1; } expected_eoc = 1; /* * Indefinite length constructed form. Find the end when enough EOCs are * found. If more indefinite length constructed headers are encountered * increment the expected eoc count otherwise just skip to the end of the * data. */ while (len > 0) { if (asn1_check_eoc(&p, len)) { expected_eoc--; if (expected_eoc == 0) break; len -= 2; continue; } q = p; /* Just read in a header: only care about the length */ if (!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len, -1, 0, 0, NULL)) { ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR); return 0; } if (inf) { if (expected_eoc == UINT32_MAX) { ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR); return 0; } expected_eoc++; } else { p += plen; } len -= p - q; } if (expected_eoc) { ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC); return 0; } *in = p; return 1; } /* * This function collects the asn1 data from a constructed string type into * a buffer. The values of 'in' and 'len' should refer to the contents of the * constructed type and 'inf' should be set if it is indefinite length. */ #ifndef ASN1_MAX_STRING_NEST /* * This determines how many levels of recursion are permitted in ASN1 string * types. If it is not limited stack overflows can occur. If set to zero no * recursion is allowed at all. Although zero should be adequate examples * exist that require a value of 1. So 5 should be more than enough. */ # define ASN1_MAX_STRING_NEST 5 #endif static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len, char inf, int tag, int aclass, int depth) { const unsigned char *p, *q; long plen; char cst, ininf; p = *in; inf &= 1; /* * If no buffer and not indefinite length constructed just pass over the * encoded data */ if (!buf && !inf) { *in += len; return 1; } while (len > 0) { q = p; /* Check for EOC */ if (asn1_check_eoc(&p, len)) { /* * EOC is illegal outside indefinite length constructed form */ if (!inf) { ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_UNEXPECTED_EOC); return 0; } inf = 0; break; } if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p, len, tag, aclass, 0, NULL)) { ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR); return 0; } /* If indefinite length constructed update max length */ if (cst) { if (depth >= ASN1_MAX_STRING_NEST) { ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING); return 0; } if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, depth + 1)) return 0; } else if (plen && !collect_data(buf, &p, plen)) return 0; len -= p - q; } if (inf) { ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC); return 0; } *in = p; return 1; } static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen) { int len; if (buf) { len = buf->length; if (!BUF_MEM_grow_clean(buf, len + plen)) { ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE); return 0; } memcpy(buf->data + len, *p, plen); } *p += plen; return 1; } /* Check for ASN1 EOC and swallow it if found */ static int asn1_check_eoc(const unsigned char **in, long len) { const unsigned char *p; if (len < 2) return 0; p = *in; if (!p[0] && !p[1]) { *in += 2; return 1; } return 0; } /* * Check an ASN1 tag and length: a bit like ASN1_get_object but it sets the * length for indefinite length constructed form, we don't know the exact * length but we can set an upper bound to the amount of data available minus * the header length just read. */ static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, char *inf, char *cst, const unsigned char **in, long len, int exptag, int expclass, char opt, ASN1_TLC *ctx) { int i; int ptag, pclass; long plen; const unsigned char *p, *q; p = *in; q = p; if (ctx && ctx->valid) { i = ctx->ret; plen = ctx->plen; pclass = ctx->pclass; ptag = ctx->ptag; p += ctx->hdrlen; } else { i = ASN1_get_object(&p, &plen, &ptag, &pclass, len); if (ctx) { ctx->ret = i; ctx->plen = plen; ctx->pclass = pclass; ctx->ptag = ptag; ctx->hdrlen = p - q; ctx->valid = 1; /* * If definite length, and no error, length + header can't exceed * total amount of data available. */ if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) { ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_TOO_LONG); asn1_tlc_clear(ctx); return 0; } } } if (i & 0x80) { ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER); asn1_tlc_clear(ctx); return 0; } if (exptag >= 0) { if ((exptag != ptag) || (expclass != pclass)) { /* * If type is OPTIONAL, not an error: indicate missing type. */ if (opt) return -1; asn1_tlc_clear(ctx); ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG); return 0; } /* * We have a tag and class match: assume we are going to do something * with it */ asn1_tlc_clear(ctx); } if (i & 1) plen = len - (p - q); if (inf) *inf = i & 1; if (cst) *cst = i & V_ASN1_CONSTRUCTED; if (olen) *olen = plen; if (oclass) *oclass = pclass; if (otag) *otag = ptag; *in = p; return 1; }